DE102008010189B4 - Apparatus and method for separating wet paint overspray - Google Patents

Abstract

A device for separating wet paint overspray from a raw gas stream (120) containing overspray particles, comprising at least two filter devices (132), each forming a closed box, and each having an inlet port (230) through which a partial raw gas stream (228) in the respective filter device (132) enters, and each comprise at least one filter element (172) for separating the overspray from the partial raw gas stream (228), the device (126) comprising at least one receptacle (176) for receiving one of filter elements (172). a plurality of filter devices (132) of cleaned material and a mixing device (204) for mechanical mixing of the cleaned material from a plurality of filter devices (132).

Description

The present invention relates to a device for separating wet paint overspray from a raw gas stream containing overspray particles, which comprises at least two filter devices which in turn each have an inlet opening through which a partial raw gas stream enters the respective filter device, and at least one filter element for each Separating the overspray from the partial crude gas stream include.

In such a device, the dry separation of the wet paint overspray is carried out from the respective partial crude gas stream, after previously a flowable, particulate, called "precoat" material filter auxiliary material was discharged into the partial crude gas stream.

This filter aid serves as a barrier to settle on the surfaces of the filter elements to prevent these surfaces from sticking to adhering overspray particles. By periodically cleaning the filter elements, the mixture of filter aid material and wet paint overspray from the filter elements passes into filter aid reservoirs from which it can be vacuumed for disposal or reuse as a filter aid. Further, the mixture of filter aid material and wet paint overspray located in the Filterhilfsmaterialaufnahmebehältern can be swirled by means of compressed air pulses from a compressed air lance so as to rise from the Filterhilfsmaterialaufnahmebehälter to the filter elements and settle there.

A critical point for the process reliability of such a device for separating wet paint overspray is the flow behavior of the mixture of filter aid material and wet paint overspray. If sufficient flow behavior no longer exists, no material exchange can take place in the filter aid material receptacles. The material in the filter aid holding containers can no longer flow to the suction opening, and the tank levels remain above the value that terminates the suction process. In this case, the painting process must be interrupted, and the material in the filter aid receiving containers must be manually loosened so that it is again flowable and thus also absorbent.

Even if the filter aid holding containers are provided with fluid bottoms in the form of sheets of sintered plastic to fluidize the material contained in the filter aid receiving containers by supplying compressed air, sufficient loosening to restore the desired flow behavior of the material can not be ensured. Namely, the adhesive properties of the particles in the mixture of filter aid material and wet paint overspray are much greater than the flow forces of the compressed air, so that the layer of the material as a whole is raised or channels are formed in the material, through which the compressed air flows upwards. In addition, fluidization of the material is complicated by the large spread in particle size distribution of the filter aid (ranging from about 2 μm to about 100 μm). To fluidize a bed of particles of 2 μm in diameter to a porosity of about 0.85, a flow rate of 0.00016 m / s is sufficient. For the fluidization of a bed of particles with a diameter of 100 microns, one needs a flow rate of 0.34 m / s, i. an approximately 2,000 times higher flow velocity than in the case of particles with a diameter of 2 microns. Even if the flow forces should outweigh the adhesive forces, therefore, can be adjusted by supplying compressed air, no uniform fluidization conditions. Rather, a classification takes place in which the fine fraction is discharged and the coarse fraction remains immobile on the bottom of the filter aid material receptacle. This classifying effect also occurs when the filter aid is swirled up by means of compressed air pulses by means of swirling devices arranged above the filter aid material receiving container.

The DE 42 11 465 C2 discloses a device for separating wet paint overspray from a raw gas stream containing overspray particles, which device comprises a single filter device forming a closed box, said filter device comprising a single inlet port through which all of the raw gas stream enters the filter device, and wherein said single filter device comprises a plurality of filter elements.

The DE 10 2005 048 580 A1 discloses a device for separating wet paint overspray from a raw gas stream containing overspray particles, this device comprising two filter devices, each of these filter devices each having an inlet opening, through which a partial raw gas stream enters the respective filter device, and in each case a plurality of filter elements for Separating the overspray from the respective partial crude gas stream comprises. This device further comprises receptacles which receive either cleaned material from the filter elements of one filter device or cleaned material from the filter elements of the other filter device.

The WO 2009/026987 A1 , which is to be considered as post-published document according to § 3 para 2 Patent Law only in the test for novelty, discloses an apparatus for separating wet paint overspray from a raw gas stream containing overspray particles, said apparatus comprising a plurality of filter devices, each form a closed box and each comprise an inlet opening, through which in each case a partial crude gas stream enters the relevant filter device, and in each case comprise a plurality of filter elements for separating the overspray from the respective partial crude gas stream. Each filter device is in each case assigned a receptacle which receives only cleaned material from the filter elements of this single filter device.

The present invention has for its object to provide a device for separating wet paint overspray of the type mentioned, which makes it possible to maintain the fluidity of the mixture of filter aid material and the filter elements cleaned wet paint overspray in the filter material storage containers in a simple and efficient manner ,

This object is achieved by a device for separating wet paint overspray according to claim 1.

The solution according to the invention is based on the concept that from several filter devices, which are each traversed by a partial crude gas stream, cleaned material from one and the same receptacle and mechanically mixed by means of a mixing device within the receptacle to in this way the adhesion between the To mechanically destroy particles of the cleaned material, to prevent "growing" of the receptacle with the cleaned material and to achieve the greatest possible homogeneity of the material present in the receptacle by the mixing of purified from different filter devices material.

This provides greater process reliability and can concentrate the material in the receptacle to higher concentrations of wet paint overspray contained therein without jeopardizing the flowability of the filter aid / wet paint overspray mixture.

If, on the other hand, each filter device is assigned its own filter aid material receptacle, then very many such filter material receptacle containers must be provided and constantly precisely controlled with regard to their material composition. Due to differential loading of the various wet-paint overspray filter devices, depending on the location of the respective filter devices relative to the application area in which the wet-paint overspray enters the raw gas stream, the concentration factor, i. the respective proportion of the wet paint overspray on the entire material located in the filter aid material receptacle, from filter aid material receptacle to filter material receptacle, differs greatly. Accordingly, the flowability of the concentrated filter aid / paint mixture is different. If the suction process is no longer carried out correctly only in a single filter aid material receptacle, this leads to a process interruption and a manual intervention. The times for material exchange must be individually set for each filter aid holding container and selected to be well above the critical range of wet paint overspray concentration. This means a high consumption of material both fresh filter aid material and with wet paint overspray loaded filter aid and correspondingly high costs for storage and transport of the filter aid.

In contrast, in the inventive device for separating wet paint overspray for several filter devices, which are each traversed by a partial raw gas stream, only a single receptacle with respect to the material level and the concentration factor must be controlled. Further, by mechanically mixing the material purified from a plurality of different filtering devices, it is possible to compensate for particularly high levels of wet paint overspray in the material cleaned from a particular filtering device by mixing with material cleaned from other filtering devices and less wet-spray oversprayed , The material contained in the larger receptacle can therefore be concentrated to a higher concentration of wet paint overspray without compromising the fluidity of the filter aid / wet paint overspray mixture.

In addition, the design effort for producing a single large receptacle is less than the cost of producing many small Filterhilfsmaterialaufnahmebehälter, which are each associated with only a single filter device.

Due to the larger interior of the plurality of filter devices associated receptacle, it is also easier possible to accommodate a suitable mixing device in the interior of the receptacle.

Preferably, the receptacle is formed as a trough extending from a region perpendicular below a first filter device into a region perpendicular under a second filter device, wherein basically any number of further filter devices can be arranged between the first filter device and the second filter device.

In a preferred embodiment of the invention it is provided that the receptacle receives cleaned material from at least three different filter devices.

The mixing device preferably has at least one mixing tool rotatable about a substantially horizontally oriented axis of rotation. As a result, a good mixing of the material contained in the receptacle is effected along the direction of the axis of rotation, so that the material in the receptacle has no concentration differences.

In order to achieve a good mixing even in long receptacles for receiving the cleaned of the filter elements of a plurality of filter devices, it can be provided that the mixing device has at least two rotatable about a substantially horizontally oriented axis of rotation rotary shafts, which in the direction of the axis of rotation behind the other are arranged.

By using a plurality of shorter rotary shafts instead of a single long rotary shaft for holding the mixing tools, the drive power required to produce a rotary motion of the mixing tools can be reduced.

In order to destroy the binding forces between the particles of the material contained in the receptacle, the mixing device may be provided with any suitable mixing tools.

In particular, it can be provided that the mixing device comprises at least one paddle, at least one ploughshare and / or at least one helix, screw or spiral.

For a thorough mixing of the material arranged in the receptacle, it is favorable if the mixing device comprises at least two filaments with opposite directions of rotation.

Since in the mechanical mixing of the material in the receptacle no Klassiereffekt occurs, in which the fines of the material is discharged from the receptacle, the particle size distribution of the filter aid in the inventive device can be chosen so that the largest possible surface is achieved, which the wet paint Embedding particles and thus detackifying.

In particular, a filter aid material can be used in which at least 20 percent by weight of the particles have a particle size of less than 2 microns.

The density of the filter aid used, for example, rock meal, may be, for example, about 2.75 g / cm ³ .

In the device according to the invention also filter aids are used whose bulk material properties are to be described as cohesive.

If the receptacle has a material outlet for the removal of wet paint overspray loaded filter aid material from the receptacle, it is advantageous if the mixing device comprises a mixing tool that assists the material discharge through the material outlet.

Further, the receptacle may include an inlet for fresh filter aid material to reduce the concentration of wet paint overspray in the receptacle in the material by the supply of fresh filter aid.

Preferably, the inlet for fresh filter aid is disposed at a first end portion of the receptacle and the receptacle has a material outlet disposed at a second end portion of the receptacle opposite the first end portion.

A particularly good mixing of the material contained in the receptacle is achieved when the mixing device sweeps over a mixing area during a complete revolution and the receptacle comprises a mixing section which has an inner contour adapted to the outer contour of the mixing area.

It is particularly favorable if the receptacle comprises a mixing section and the mixing device sweeps over substantially the entire mixing section of the receptacle during a complete revolution.

Preferably, it is provided that during normal operation of the device, substantially all of the material received by the receptacle is arranged in the mixing section of the receptacle.

The mixing section of the receptacle can in particular be substantially cylindrical or cylindrical-section-shaped.

It is preferably provided that differences in the concentration of wet paint overspray in the material purified from different filter devices are compensated by the mechanical mixing.

The present invention further relates to a method for separating wet paint overspray from a raw gas stream containing overspray particles.

Another object of the present invention is to provide such a process for separating wet paint overspray, which makes it possible to maintain a sufficient flowability of the mixture of filter aid material and filter element-cleaned wet paint overspray in the filter aid material reservoirs in a simple and efficient manner.

• - Aufteilen des Rohgasstroms in mindestens zwei Teil-Rohgasströme, die durch verschiedene Einlassöffnungen in mindestens zwei verschiedene Filtervorrichtungen eintreten, welche jeweils eine geschlossene Box bilden und jeweils mindestens ein Filterelement zum Abtrennen des Oversprays aus dem jeweiligen Teil-Rohgasstrom umfassen;
• - Abtrennen des Oversprays aus den Teil-Rohgasströmen mittels der Filterelemente;
• - Abreinigen von Material von den Filterelementen mehrerer verschiedener Filtervorrichtungen;
• - Auffangen des abgereinigten Materials aus den mehreren verschiedenen Filtervorrichtungen in demselben Aufnahmebehälter;
• - mechanisches Durchmischen des abgereinigten Materials aus den mehreren verschiedenen Filtervorrichtungen in dem Aufnahmebehälter mittels einer Mischvorrichtung.

This object is achieved by a method for separating wet paint overspray from a raw gas stream containing overspray particles, which comprises the following method steps:

• - Divide the raw gas stream into at least two partial crude gas streams entering through different inlet openings in at least two different filter devices, each forming a closed box and each comprise at least one filter element for separating the overspray from the respective partial crude gas stream;
• - separating the overspray from the partial raw gas streams by means of the filter elements;
• - cleaning material from the filter elements of several different filter devices;
• - Collecting the cleaned material from the several different filter devices in the same receptacle;
• - Mechanical mixing of the cleaned material from the several different filter devices in the receptacle by means of a mixing device.

The receptacle is preferably arranged directly vertically below the filter devices from which the receptacle receives cleaned material.

Furthermore, it can be provided that the partial crude gas streams are at least partially passed through the receptacle to thereby receive filter aid material from the receptacle.

Further features and advantages of the invention are the subject of the following description and the drawings of exemplary embodiments.

• 1 einen schematischen vertikalen Querschnitt durch eine Lackierkabine mit einer darunter angeordneten Vorrichtung zum Abtrennen von Nasslack-Overspray aus einem Overspray-Partikel enthaltenden Rohgasstrom, welche eine unter der Lackierkabine angeordnete Strömungskammer und auf beiden Seiten der Strömungskammer jeweils mehrere Filtermodule umfasst;
• 2 einen der 1 entsprechenden schematischen vertikalen Querschnitt durch die Anlage aus 1, wobei zusätzlich die jeweilige Strömungsrichtung des Rohgases, der aus den Filtermodulen austretenden Abluft und der zur Erzeugung von Querluftschleiern in die Strömungskammer eingespeisten Zuluft durch Pfeile angezeigt sind;
• 3 eine schematische Draufsicht von oben auf die Anlage aus den 1 und 2;
• 4 eine schematische perspektivische Darstellung eines einzelnen Filtermoduls, das zur Anordnung zwischen zwei benachbarten weiteren Filtermodulen vorgesehen ist (Mittelmodul);
• 5 eine schematische Vorderansicht des Filtermoduls aus 4;
• 6 einen schematischen Querschnitt durch ein Filtermodul und einen darunter angeordneten Aufnahmebehälter mit Mischvorrichtung;
• 7 einen schematischen Längsschnitt durch drei in einer Längsrichtung der Anlage aufeinanderfolgende Filtermodule und einen unter den Filtermodulen angeordneten Aufnahmebehälter mit einer Mischvorrichtung;
• 8 eine schematische Seitenansicht einer Mischvorrichtung mit zwei Wendeln mit entgegengesetztem Drehsinn, welche um eine horizontale Drehachse drehbar sind;
• 9 eine schematische Seitenansicht von zwei Gruppen von jeweils vier Filtermodulen, wobei jeder Gruppe von Filtermodulen ein Aufnahmebehälter mit einer Mischvorrichtung zum Durchmischen von aus den Filtermodulen jeweils einer Gruppe abgereinigtem Material zugeordnet ist; und
• 10 eine schematische Seitenansicht einer Gruppe von acht Filtermodulen, wobei dieser großen Gruppe von Filtermodulen ein einziger langer Aufnahmebehälter zugeordnet ist, dessen Mischvorrichtung zwei um eine im wesentlichen horizontal ausgerichtete Drehachse drehbare Drehwellen zur Halterung von Mischwerkzeugen aufweist, welche in Richtung der Drehachse hintereinander angeordnet sind.

In the drawings show:

• 1 a schematic vertical cross-section through a paint booth with a device arranged underneath for separating wet paint overspray from a raw gas stream containing overspray particles, which comprises a arranged under the spray booth flow chamber and on both sides of the flow chamber in each case a plurality of filter modules;
• 2 one of the 1 corresponding schematic vertical cross section through the plant 1 , wherein in addition the respective flow direction of the raw gas, the exhaust air emerging from the filter modules and the supply air fed into the flow chamber to produce transverse air curtains are indicated by arrows;
• 3 a schematic plan view from above of the plant from the 1 and 2 ;
• 4 a schematic perspective view of a single filter module, which is provided for the arrangement between two adjacent further filter modules (center module);
• 5 a schematic front view of the filter module 4 ;
• 6 a schematic cross section through a filter module and arranged underneath a receptacle with mixing device;
• 7 a schematic longitudinal section through three successive in a longitudinal direction of the system filter modules and arranged under the filter modules receptacle with a mixing device;
• 8th a schematic side view of a mixing device with two coils in opposite directions of rotation, which are rotatable about a horizontal axis of rotation;
• 9 a schematic side view of two groups of four filter modules, each group of filter modules is associated with a receptacle with a mixing device for mixing of the filter modules in each case a group of cleaned material; and
• 10 a schematic side view of a group of eight filter modules, this large group of filter modules is associated with a single long receptacle, the mixing device two by one in the Has substantially horizontal axis of rotation rotatable rotary shafts for holding mixing tools, which are arranged one behind the other in the direction of the axis of rotation.

Identical or functionally equivalent elements are denoted by the same reference numerals in all figures.

One in the 1 to 7 illustrated, as a whole with 100 designated plant for spray painting of vehicle bodies 102 comprises a conveying device shown purely schematically 104 , by means of which the vehicle bodies 102 along a conveying direction 106 through an application area 108 can be moved as a whole with 110 designated paint booth.

The application area 108 is the interior of the paint booth 110 , which in a direction perpendicular to the conveying direction 106 , the longitudinal direction of the paint booth 110 corresponds, extending horizontal transverse direction 112 on both sides of the conveyor 104 through each cabin wall 114 is limited.

On both sides of the conveyor 104 are in the paint booth 110 spray-painting 116 , For example, in the form of painting robots arranged.

By means of a (only partially shown) Umluftkreislaufs an air flow is generated, which is the application area 108 essentially vertically interspersed from top to bottom, as in 2 through the arrows 118 is indicated.

This airflow decreases in the application area 108 Paint overspray in the form of overspray particles. The term "particles" encompasses both solid and liquid particles, in particular droplets.

When using wet paint, the wet paint overspray consists of paint droplets. Most of the overspray particles have a largest dimension in the range of about 1 μm to about 100 μm.

The one with the overspray particles from the application area 108 laden exhaust air flow is referred to below as the raw gas stream. The flow direction of the raw gas stream is in the 2 and 6 through arrows 120 shown.

The raw gas stream leaves the paint booth 110 down and enters a designated as a whole by 126 device for separating wet paint overspray from the raw gas stream, which below the application area 108 is arranged.

The device 126 includes a substantially cuboid flow chamber 128 , which are in the conveying direction 106 over the entire length of the paint booth 110 extends and in the transverse direction 112 through vertical side walls 130 is limited, which essentially with the side cabin walls 114 the paint booth 110 aligned, leaving the flow chamber 128 has substantially the same horizontal cross-sectional area as the paint booth 110 and substantially completely within the vertical projection of the base of the paint booth 110 is arranged.

How best 7 It can be seen on both sides of the flow chamber 128 in each case several, for example three, filter modules 132 arranged, which two are in the longitudinal direction 134 (which with the conveying direction 106 matches) of the device 126 for removing wet paint overspray extending module rows 136 form.

Each of the module rows 136 includes two corner modules 138 , which each one end of a module row 136 form, and at least one between two adjacent filter modules 132 arranged center module 140 ,

Each of the filter modules 132 is as a preassembled unit 154 formed, which is manufactured at a location remote from the installation of the paint shop and transported as a unit to the installation of the paint shop. At the installation site, the preassembled unit 154 arranged in the intended working position and with one or more adjacent preassembled units 154 as well as with a carrying structure of the application area 108 connected.

The structure of a filter module 132 becomes the example of a middle module 140 with reference to the following 4 and 5 described:

The module includes a support structure 156 from two vertical rear supports 158 and two vertical front pillars 160 , which at their upper end over horizontal cross struts 162 each with one of the rear supports 158 are connected ( 4 ).

Furthermore, the front supports 160 connected at their upper ends by means of another (not shown) cross member.

Also the rear supports 158 are interconnected by means of transverse struts (not shown) or by means of a connecting frame (not shown).

The cross struts at the top of the support structure 156 carry a horizontal ceiling wall 164 ,

At the front of the front supports 160 is a vertical front wall 166 of the filter module 132 held.

The ceiling wall 164 and the front wall 166 form partitions 168 of the filter module 132 which one inside the filter module 132 arranged filter element receiving space 170 from outside the filter module 132 located area of the flow chamber 128 separate.

At two in a row of modules 136 juxtaposed filter modules 132 in a simple way and stable to connect to each other or to a filter module 132 with an adjacent boundary wall of the flow chamber 128 To connect, includes the support structure 156 each filter module 132 at least one rear support 158 one vertically and in the transverse direction 112 aligned, substantially flat contact surface 242 having, which to a corresponding contact surface 242 an adjacent filter module 132 or can be applied to an adjacent boundary wall.

The for connection to an adjacent filter module 132 serving rear prop 158 preferably has an approximately U-shaped profile.

How out 4 can be seen, has each middle module 140 two rear supports 158 with U-shaped profiles whose open sides face each other so that the center module 140 on both sides with an adjacent further filter module 132 is connectable.

Every corner module 138 however, has only one rear support 158 with U-shaped profile on; the opposite rear support 158 which does not work with an adjacent filter module 132 must be connected, for example, may have a T-shaped profile to increase their mechanical strength instead of a U-shaped profile.

Incidentally, the corner modules are right 138 in terms of design and function with the center modules described in detail above 140 match.

In the filter element receiving space 170 each filter module 132 are several, for example ten, filter elements 172 arranged in two rows one above the other, which of a common body 174 standing at the backs of the rear props 158 is held, stand in a horizontal direction.

The filter elements 172 For example, they may be formed from sheets of sintered polyethylene provided with a polytetrafluoroethylene (PTFE) membrane on their outer surface.

The PTFE coating serves the filter class of the filter elements 172 to increase (ie reduce their permeability) and also to prevent the permanent adhesion of the separated from the raw gas stream wet paint overspray.

Both the base material of the filter elements 172 as well as their PTFE coating have a porosity, so that the raw gas through the pores in the interior of the respective filter element 172 can get.

In order to prevent sticking of the filter surfaces, they are further provided with a barrier layer of filter aid material discharged into the raw gas stream. This preferably particulate filter aid is commonly referred to as "precoat" material.

The barrier layer forms during operation of the device 126 by deposition of the in the raw gas stream 120 discharged filter aid to the filter surfaces and prevents the filter surfaces stick by adhering wet paint overspray.

Filter aid material from the raw gas stream 120 also sits on the insides of the ceiling wall 164 and the front wall 166 of the filter module 132 where it also prevents adhesion of wet paint overspray.

In principle, any medium which is capable of absorbing the liquid fraction of the wet-paint overspray can be used as the filter aid.

In particular, suitable as filter aids, for example, lime, stone powder, aluminum silicates, aluminum oxides, silicon oxides, powder coating or the like into consideration.

Alternatively or additionally, as a filter aid for receiving and / or binding of the overspray and particles having a cavity structure and relative to their outer dimensions large inner surface can be used, for example zeolites or other hollow, such as spherical body of polymers, glass or aluminum silicate and / or natural or synthetically produced fibers.

Alternatively or additionally, as a filter aid for receiving and / or binding the overspray also chemically reactive with the overspray particles are used, for example, chemically reactive particles of amine, epoxy, carboxyl, hydroxyl or isocyanate groups, chemically reactive particles of octylsilane aftertreated alumina or solid or liquid mono-, oligo- or polymers, silanes, silanols or siloxanes.

The filter aid preferably consists of a plurality of filter aid particles having a mean diameter in the range, for example, from about 10 μm to about 100 μm.

To be able to add the filter aid material to the raw gas stream without the risk that the filter aid material in the application area 108 the paint shop 100 passes and, together with wet paint overspray from the filter elements 172 To be able to capture cleaned filter aid material is each group of several, for example three, filter modules 132 each a common receptacle 176 associated, which is in the longitudinal direction 134 the device 126 over the entire length of, for example, three, associated filter modules 132 extends (see 7 ).

The receptacle 176 is substantially trough-shaped and includes an upper inlet portion 178 as well as down to the entry section 178 subsequent mixing section 180 ,

The entry section 178 is by two perpendicular to the longitudinal direction 134 running end walls 182 and two opposite each other, from the one end wall 182 to the other end wall 182 extending and inclined against the vertical at an angle of at least about 30 ° sidewalls 184 limited.

The down to the inlet section 178 subsequent mixing section 180 is formed substantially cylindrical and has a cylinder over a circumferential angle of, for example, about 270 ° extending, cylinder-shaped shell wall 186 on whose upper edges are at the lower edges of the side walls 184 of the entry section 178 of the receptacle 176 connect so that the mixing section 180 upwards to the entry section 178 opens.

On one of the side walls 184 of the entry section 178 of the receptacle 176 is a fluidizing device 198 held, which serves to compressed air pulses in the underlying, in the receptacle 176 delivered material to whirl up this material and so this material, including the filter aid contained therein, in through the inlet section 178 of the receptacle 176 introduce introduced raw gas stream.

During operation of the system 100 becomes the Aufwirbelungseinrichtung 198 intermittently, for example, four times a minute for about 5 seconds each, put into operation.

The Aufwirbelungseinrichtung 198 includes several, for example, at least two per filter module 132 , Outlet nozzles 200 for compressed air, which are designed as conical nozzles and each one down to the mixing section 180 of the receptacle 176 can generate expanding compressed air cone.

The outlet nozzles 200 are on a compressed air pipeline 196 arranged through one of the side walls 184 of the entry section 178 of the receptacle 176 passed and to one outside of the receptacle 176 arranged compressed air source 202 leads.

In the mixing section 180 of the receptacle 176 is a mixing device 204 for thorough mechanical mixing of the filter elements 172 the different filter modules 132 cleaned material containing the mixing section 180 up to a filling level 206 stuffed, arranged ( 6 ).

How best 7 can be seen, includes the mixing device 204 a rotary shaft 208 , which are parallel to the longitudinal direction 134 the device 126 extends and by means of bearings 210 on the end walls 182 of the receptacle 176 around a horizontal, parallel to the longitudinal direction 134 extending axis of rotation 212 is rotatably mounted.

An end of the rotary shaft 208 is through one of the end walls 182 of the receptacle 176 fluid-tight and passed to an outside of the receptacle 176 arranged rotary drive 214 (For example, an electric drive motor) coupled.

The rotary shaft 208 the mixing device 204 can extend over the entire length of the paint booth 118 extend for example about 20 m away.

The filling volume of the material in the mixing section 180 of the receptacle 176 may for example be at least 750 l.

At the rotary shaft 208 are non-rotatable with the same several mixing tools 216 disposed which, for example, as a paddle 218 or may be formed as plowshares.

The inner contour of the mixing section 180 of the receptacle 176 is so on the outer contour of the mixing tools 216 the mixing device 204 adapted that the mixing tools 216 at a complete revolution of the rotary shaft 208 the mixing device 204 around its axis of rotation 212 a mixing area 220 sweep whose outer contour substantially the inner contour of the mixing section 180 of the receptacle 176 equivalent.

Preferably, the mixing device passes over 204 in a complete revolution about its axis of rotation 212 essentially the entire mixing section 180 of the receptacle 176 ,

By means of the rotary drive 214 driven mixing movement of the mixing device 204 are the binding forces between the particles that make up the receptacle 176 material is destroyed and a mixing of the material in the longitudinal direction of the rotary shaft 208 causes it inside the receptacle 176 There are no differences in concentration and in particular the ratio of fresh filter aid on the one hand and the filter elements 172 cleaned filter aid and wet paint overspray on the other hand everywhere in the receptacle 176 is essentially the same size.

To the receptacle 176 feeding fresh filter aid is on an end wall 182 of the receptacle 176 an inlet 222 for fresh filter aid which is connected to a source of fresh filter aid (not shown).

At the inlet 222 for fresh filter aid opposite end wall 182 is a material outlet 224 provided, which in the lower part of the mixing section 180 near the lower tip of the cylindrical mixing section 180 , is arranged.

Through this material outlet 224 can with wet paint overspray enriched filter aid from the receptacle 176 be discharged, despite the supply of fresh filter aid material through the inlet 222 a substantially constant level 206 in the receptacle 176 maintain.

Near the material outlet 224 is at the rotary shaft 208 , in the radial direction or also on the front side, in the axial direction, of the rotary shaft 208 sticking out, a mixing tool 216 ' arranged, which the material discharge through the material outlet 224 supported.

Instead of as a single, in the radial direction of the rotary shaft 208 protruding paddles 218 can the mixing tools 216 the mixing device 204 also as a coaxial to the axis of rotation 212 the mixing device 204 trained helix 226 be educated.

In particular, the mixing device 204 with two coils 226 . 226 ' be provided with opposite direction of rotation.

These spirals can have the same pitch, but different radii.

Due to the opposite direction of rotation of the two coils 226 . 226 ' is a particularly good mixing of the mixing section 180 reached existing material.

By operating the mixing device 204 is also the surface of the receptacle 176 smoothed material, and in the receptacle 176 optionally formed by subsoil material bridges are broken.

To get out of the flow chamber 128 into the filter modules 132 entering raw gas flow in each case a filter module 132 assigned partial raw gas streams 228 to divide these partial raw gas streams 228 specifically in the entry section 178 each of a receptacle 176 deflect in and direct access of the raw gas flow from the flow chamber 182 to the filter elements 172 To prevent this is every filter module 132 with a slot-shaped inlet opening 230 provided as an inlet duct 232 is formed, the one in the flow direction of the partial raw gas stream 228 up to a bottleneck 234 has narrowing flow-through cross-section.

Alternatively or additionally, it can also be provided that the inlet channel 232 a in the flow direction of the raw gas stream from a bottleneck 234 has expanding through-flow cross-section.

The inlet channel 232 is down through an inlet slope 236 extending from the front supports 160 the support structure 156 from obliquely upward at an angle of, for example, about 40 ° to about 65 ° to the horizontal.

The inlet slope 236 extends in the longitudinal direction 134 the flow chamber 128 over substantially the entire length of the inlet opening 230 from, for example, about 1 m to about 2 m, which is nearly the extent of the entire filter module 132 in the longitudinal direction 134 equivalent.

At the top, the inlet opening 230 through the lower edge of the front wall 166 and through one of the lower edge of the front wall 166 diagonally down into the interior of the filter module 132 protruding upper baffle 238 limited.

The upper baffle 238 is inclined at an angle of, for example, about 55 ° to about 70 ° to the horizontal and extends in the longitudinal direction 134 over substantially the entire width of the inlet opening 230 for example, 1 m or 2 m.

Through this upper baffle 238 for the partial crude gas stream 228 it is achieved that the raw gas flow is not on the front wall 166 of the filter module 132 tears off, but directly into the receptacle 176 is directed into (see 6 ).

During operation of the filter module 132 is the upper baffle 238 provided with a coating of the filter aid, so that the upper baffle 238 Easy to clean and no overspray directly on the top baffle 238 sticking.

By the above-described embodiment of the geometry of the inlet opening 230 will reach that inlet opening 230 a bottleneck 234 at which the flow-through cross-section of the inlet opening 230 smallest and therefore the raw gas velocity is greatest.

Preferably, the raw gas velocity in the throat is from about 2 m / s to about 8 m / s, more preferably from about 3 m / s to about 5 m / s.

In this way it is effectively prevented that filter aid material from the interior of the filter module 132 , which forms a closed box, into the flow chamber 128 and from there into the application area 108 arrives. The fluidization of the filter aid in the receptacle 176 and the cleaning of the filter elements 172 can therefore be done at any time, without the supply of raw gas to the filter module 132 or even the operation of the spray painting equipment 116 in the application area 108 to have to interrupt.

Furthermore, characterized in that the partial crude gas stream 228 in the receptacle 176 directed from the respective inlet opening 230 ensures that a diversion of the partial raw gas flow 228 in the entry section 178 of the receptacle 176 he follows. As a result, a sufficient amount of filter aid, by the swirling from the in the receptacle 176 template is generated by the partial crude gas stream 228 carried away.

The raw gas flow from the flow chamber 128 through the inlet opening 230 into the interior of the filter module 132 is in 6 shown schematically. It can clearly be seen that in the interior of the filter module 132 forms a flow roll with a horizontal axis.

On the inlet opening 230 opposite side of the receptacle 176 the raw gas flow laden with filter aid material flows out of the inlet section again 178 of the receptacle 176 out and then spreads over the entire depth of the filter element receiving space 170 , causing a swirl around the filter elements 172 is formed and due to the high dynamics of the partial raw gas stream 228 in the bottleneck 234 has received a homogeneous distribution of the filter aid to the individual filter elements 172 is guaranteed.

In the operation of each filter module 132 passes into the respective filter module 132 entering partial crude gas stream 228 the filter surfaces of the filter elements 172 wherein both the entrained filter aid material and the entrained wet paint overspray are deposited on the filter surfaces, and the filtered tube gas passes as exhaust air flow through the porous filter surfaces into the interiors of the filter elements 172 that with a cavity inside the main body 174 from which the filter elements 172 stand up, are connected. From this cavity, the purified exhaust air flow passes in each case an exhaust pipe 248 that of the main body 174 the filter elements 172 each filter module 132 to about the middle of the flow chamber 128 arranged and parallel to the longitudinal direction 134 the flow chamber 128 extending exhaust duct 250 leads (see in particular the 1 and 2 ).

The flow direction of the exhaust air flow is in 2 through the arrows 252 specified.

The exhaust air from the exhaust duct cleaned by the wet paint overspray 250 arrives at a (not shown) exhaust fan, from where the cleaned exhaust air via a (not shown) cooling register and a (not shown) supply line one above the application area 108 arranged (not shown) air chamber, the so-called plenum, is supplied.

From this air chamber, the purified exhaust air passes through a filter cover in the application area 108 back.

From the supply line branches off a (not shown) exhaust duct, through which a part of the cleaned exhaust air flow is discharged (for example via a fireplace) to the environment.

This discharged to the environment part of the exhaust air flow is replaced by fresh air, which in the flow chamber 128 about two air curtain generating devices 254 is fed, each via a supply air line 256 are connected to a supply air system (not shown) ( 1 and 2 ).

Each of the air curtain generating devices 254 each generates an air curtain, which of the respective associated air curtain generating device 254 starting in a substantially horizontal direction along the tops of the ceiling walls 164 the filter modules 132 to a bottleneck 262 between the upper edges of the opposite rows of modules 136 is directed and thereby prevents the loaded with the wet paint overspray raw gas stream 120 from the application area 108 to the top of the filter modules 132 passes and the wet paint overspray from the raw gas stream 120 at the top of the filter modules 132 settles.

The mean flow direction of the air in the air curtain generating devices 254 generated transverse air curtains at the top of the filter modules 132 is in 2 through the arrows 264 illustrated.

The majority of through the application area 108 The air passed through is thus guided in a recirculating air circuit, which covers the application area 108 , the flow chamber 128 , the filter modules 132 , the exhaust pipes 248 , the exhaust duct 250 , the exhaust fan as well as the supply line and the air chamber above the application area 108 comprising, wherein a constant heating of the guided air in the circulating air through the fresh air supply via the air curtain generating devices 254 is avoided.

Since the separation of the wet paint overspray from the partial crude gas streams 228 by means of the filter elements 172 dry, ie without leaching with a cleaning liquid occurs, the air guided in the recirculation air is not moistened when separating the wet paint overspray, so that no devices for dehumidifying the air circulated in the recirculation air are required.

Furthermore, no devices for the separation of wet paint overspray from a washout cleaning liquid are required.

The filter elements 172 the filter modules 132 At certain time intervals, when their loading with wet paint overspray and filter aid material has reached a predetermined level, cleaned by compressed air pulses.

This cleaning can (depending on the pressure loss increase on the filter elements 172 ) take place, for example, once to six times per 8-hour working shift, ie approximately every 1-8 hours.

The required compressed air pulses are generated by means of a (not shown) Abpulseinheit, which on the body 174 the filter elements 172 each filter module 132 is arranged, wherein the Abpulseinheit is capable of delivering compressed air pulses to compressed air pipes, which within the respective body 174 run and lead from the Abpulseinheit in the interiors of the filter elements.

From the interiors of the filter elements 172 the compressed air pulses pass through the porous filter surfaces into the filter element receiving space 170 in which the barrier layer of filter aid material and the wet paint overspray deposited on the filter surfaces are detached from the filter surfaces, so that the filter surfaces are returned to their cleaned-up original state.

The filter aid is in the apparatus described above 126 for separating wet paint overspray exclusively by stirring up the filter aid in the respective associated receptacle 176 the partial crude gas streams 228 added.

In the receptacle 176 The device comprises accumulated filter aid material mixed with overspray and to be able to be disposed of or recycled 126 for separating wet paint overspray, a filter aid material removal device (not shown) connected to the material outlets 224 the receptacle 176 is connected and, for example, a suction fan for sucking the material from the receptacles 176 includes.

This from the receptacles 176 taken material containing filter aid with overspray particles can either be disposed of or - if necessary, after a treatment - at least partially reused in the coating plant.

An in 9 in a schematic side view of a module row 136 illustrated second embodiment of a device 126 for separating wet paint overspray differs from the apparatus described above 126 in that not all in the longitudinal direction 134 the device 126 arranged one behind the other filter modules 132 a module row 136 a single receptacle 176 extending over the entire length of the module row 136 extends, but that instead each row of modules 136 in several, for example two, module groups 266a . 266b each with several, for example four, filter modules 132 is divided and each module group 266a . 266b one receptacle each 176a respectively. 176b associated with which of the filter elements 172 the filter modules 132 the respective module group 266a . 266b cleaned material (filter aid and wet paint overspray) absorbs.

In this embodiment of the device 126 for separating wet paint overspray so are each at least two receptacles 176a . 176b in the longitudinal direction 134 arranged sequentially, but still each receptacle 176a . 176b that from several filter modules 132 picks up cleaned material.

Further, each of the receptacles has 176a . 176b one mixing device each 204 on, by means of which from different filter modules 132 originating and from the respective receptacle 176a . 176b Trapped material is mixable.

In this embodiment, the end walls 182 the receptacle 176a . 176b not vertically formed, but have a the inlet section 178 frontally limiting upper inclined end wall section 268 which is inclined relative to the vertical, that the inclined end wall portion 268 in the longitudinal direction 134 over the mixing section 180 of the relevant receptacle 176a . 176b survives. As a result, under the inclined end wall sections 268 from in the longitudinal direction 134 successive receptacles 176a . 176b and between the end walls of the mixing sections 180 this receptacle 176a . 176b enough space to accommodate one rotary drive each 214 a mixing device 204 created.

Furthermore, make sure that between the exhaust pipes 248 and the receptacles 176a . 176b enough space to remove the rotary shaft 208 each of a mixing device 204 is available.

The in the longitudinal direction 134 the device 126 successively arranged module groups 266a . 266b can be assigned to different paint booths or different Lackierabschnitten within the same spray booth, for example, a Lackierabschnitt for the interior painting of the vehicle bodies 102 on the one hand and a painting section for the exterior painting of the vehicle bodies 102 on the other hand.

Alternatively, it can also be provided that in the various painting sections, which the module groups 266a . 266b are assigned, different types of paint on the vehicle bodies 102 be applied, for example, a base coat on the one hand and a clearcoat on the other.

In the above that between the module groups 266a . 266b lying area of the paint shop is no paint on the vehicle bodies 102 applied.

Incidentally, the in 9 illustrated second embodiment of a device 126 for separating wet paint overspray in terms of design and function with in the 1 to 8th illustrated in the first embodiment, reference is made to the above description in this regard.

An in 10 in a schematic side view of a module row 136 illustrated third embodiment of a device 126 for separating wet paint overspray differs from that in the 1 to 8th illustrated first embodiment in that the number of filter modules 132 , which the same receptacle 176 are larger (for example, eight filter modules 132 ), so the receptacle 176 a very large extension in the longitudinal direction 134 the device 126 (For example, 16 m or more).

With such a large length of the receptacle 176 would have a rotary drive 214 used with a very high drive power to stretch over the entire length of the receptacle 176 extending, with mixing tools 216 provided rotary shaft 208 to drive to a rotary motion.

At the in 10 illustrated third embodiment is therefore intended that the mixing device 204 two in the longitudinal direction 134 and in the direction of the common axis of rotation 212 consecutive rotary shafts 208a . 208b having, each of its own rotary drive 214a . 214b be driven and each in a warehouse 272 in the middle of the receptacle 176 as well as on the front end wall 182a or at the rear end wall 182b of the receptacle 176 are rotatably mounted.

Each of the rotary shafts 208a . 208b is with one or more mixing tools 216 , for example, with spirals 226 , for mixing in the receptacle 176 provided recorded material.

By dividing the mixing tools 216 on two separately mounted and driven rotary shafts 208a . 208b can be used for generating the rotary motion of the mixing tools 216 required drive power of the rotary actuators 214a . 214b be reduced.

Also in this third embodiment, the end walls 182a . 182b of the receptacle 176 not vertically formed, but have a the inlet section 178 frontally limiting upper inclined end wall section 268 which is inclined relative to the vertical, that the inclined end wall portion 268 in the longitudinal direction 134 over the mixing section 180 of the receptacle 176 survives.

As a result, under the inclined end wall sections 268 enough space to accommodate one rotary drive each 214a . 214b the mixing device 204 created.

Incidentally, the in 10 illustrated third embodiment of a device 126 for separating wet paint overspray in terms of design and function with in the 1 to 8th illustrated in the first embodiment, reference is made to the above description in this regard.

Claims (15)

A device for separating wet paint overspray from a raw gas stream (120) containing overspray particles, comprising at least two filter devices (132), each forming a closed box, and each having an inlet port (230) through which a partial raw gas stream (228) in the respective filter device (132) enters, and each comprise at least one filter element (172) for separating the overspray from the partial raw gas stream (228), the device (126) comprising at least one receptacle (176) for receiving one of filter elements (172). a plurality of filter devices (132) of cleaned material and a mixing device (204) for mechanical mixing of the cleaned material from a plurality of filter devices (132). Device after Claim 1 characterized in that the receptacle (176) is formed as a trough extending from a region perpendicular below a first filter device (132) to a region perpendicular below a second filter device (132). Device according to one of Claims 1 or 2 , characterized in that the receptacle (176) receives cleaned material from at least three filter devices (132). Device according to one of Claims 1 to 3 characterized in that the mixing device (204) comprises at least one mixing tool (216) rotatable about a horizontally oriented axis of rotation (212). Device after Claim 4 , characterized in that the mixing device (204) at least two about a horizontally oriented axis of rotation (212) rotatable rotary shafts (208), which are arranged in the direction of the axis of rotation (212) one behind the other. Device according to one of Claims 1 to 5 , characterized in that the mixing device (204) at least one paddle (218), at least one ploughshare and / or at least one coil (226, 226 ') comprises. Device according to one of Claims 1 to 6 , characterized in that the mixing device (204) comprises at least two helices (226, 226 ') with opposite directions of rotation. Device according to one of Claims 1 to 7 characterized in that the receptacle (176) has a material outlet (224) and that the mixing device (204) comprises a mixing tool (216 ') which assists in dispensing material through the material outlet (224). Device according to one of Claims 1 to 8th , characterized in that the receptacle (176) has an inlet (222) for fresh filter aid material. Device after Claim 9 characterized in that the fresh filter aid inlet (222) is disposed at a first end portion of the receptacle (176), and the receptacle (176) has a material outlet (224) disposed at a second end portion of the receptacle (16) opposite the first end portion (176). 176) is arranged. Device according to one of Claims 1 to 10 , characterized in that the mixing device (204) sweeps over a mixing area (220) during a complete revolution and that the receptacle (176) comprises a mixing section (180) which has an inner contour adapted to the outer contour of the mixing area (220). Device according to one of Claims 1 to 11 , characterized in that the receptacle (176) comprises a mixing section (180) and that the mixing device (204) sweeps over the entire mixing section (180) of the receptacle (176) in one complete revolution. Device according to one of Claims 11 or 12 , characterized in that the mixing section (180) of the receptacle (176) is cylindrical or cylindrical-section-shaped. Device according to one of Claims 1 to 13 , characterized in that differences in the concentration of wet paint overspray in the material purified from different filter devices (132) are compensated by the mechanical mixing. A method for separating wet paint overspray from a raw gas stream (120) containing overspray particles, comprising the following method steps: - Dividing the raw gas stream (120) into at least two partial raw gas streams (228) entering through different inlet openings (230) in at least two different filter devices (132), each forming a closed box and at least one filter element (172) for separating the overspray from the respective partial raw gas stream (228) include; - separating the overspray from the partial raw gas streams (228) by means of the filter elements (172); - cleaning material from the filter elements (172) of a plurality of different filter devices (132); - collecting the cleaned material from the several different filter devices (132) in the same receptacle (176); - mechanical mixing of the cleaned material from the several different filter devices (132) in the receptacle (176) by means of a mixing device (204).

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